Method and apparatus for displaying and/or recording measured values

ABSTRACT

A method and apparatus for compiling, evaluating and displaying measured values which are dependent on a given independent variable obtained during a measuring period within a sequence of measuring periods whereby the display may take place at a time and location other than when the measured values are obtained and at a speed independent of the measuring speed. The measured values are, preferably after quantizing, stored in a memory with an identifying or address indication for each value and the information is read out for display, starting at any point in time with respect to the measuring period, by correlating the identifying or address indication with a location indication for the display mechanism so as to synchronize the timing read out of a particular measurement with the display location associated with such measurement.

United States Patent Grada et al.

[ 1 March 6, 1973 8/1970 Kietz ..340/3 R Primary Examiner-Richard A. Farley AttrneySpencer & Kaye ABSTRACT A method and apparatus for compiling, evaluating and displaying measured values which are dependent on a given independent variable obtained during a measuring period within a sequence of measuring periods whereby the display may take place at a time and location other than when the measured values are obtained and at a speed independent of the measuring speed. The measured values are, preferably after quantizing, stored in a memory with an identifying or address indication for each value and the information is read out for display, starting at any point in time with respect to the measuring period, by correlating the identifying or address indication with a location inthe display mechanism so as to synchronize the timing read out of a particular measurement with the display location associated with such measurement.

82 Claims, ll Drawing Figures METHOD AND APPARATUS FOR 3,523,276

DISPLAYING AND/OR RECORDING MEASURED VALUES [75] Inventors: Walter Grada; Heinz Purnhagen,

both of Bremen, Germany; Giinter [57] Schnell, Struer, Denmark; Wolfgang Stedtnitz, Neukrug, Germany [73] Assignee: Fried Krupp Gesellschaft mit beschraenkter Haftung, Essen, Germany [22] Filed: May 18, 1971 [21] App]. No.: 144,539

[30] Foreign Application Priority Data May 25, 1970 Germany ..P 405.1

[52] U.S. Cl. ..340/3 R, 343/5 DP [51] Int. Cl ..G01s 9/68 dlcatlon for [58] Field of Search ..340/l R, 3 C, 3 F, l C, 3 R, 340/5 R; 343/5 DP, 7 A

[56] References Cited UNITED STATES PATENTS 3,437,986 4/1969 Noble ..340/3 R Id stylus Drive Counter P7,

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METHOD AND APPARATUS FOR DISPLAYING AND/OR RECORDING MEASURED VALUES BACKGROUND OF THE INVENTION The present invention relates to a method for compiling, evaluating, measured values obtained during a measuring period within a sequence of measuring periods and dependent upon a given independent value and for displaying and/or recording same preferably in the form of a columnar arrangement with the display and/or recording, if required, taking place at a location and time other than where the information was obtained, and if required, with the simultaneous offering of additional information of a physical type different from that of the measured values. The present invention moreover relates to apparatus for performing this method.

In the measuring art and in the data processing art numerous methods and appropriately designed systems are known for determining, possibly converting and otherwise processing values which are stored in intermediate stores and finally displayed and/or recorded. For example, such systems may utilize digital or analog memories, particularly for the intermediate storage, before a further evaluation, perhaps by means of computer controlled drafting apparatus. Less expensive regarding the required apparatus are systems utilizing a graphic display, and perhaps storage of measured values determined over an independent variable on a cathode-ray tube screen or in the form of curves on a dot or a line printer. A special variation of the latter, known particularly from the echo sounding art, is the echograph which produces a continuous diagram and which similar to conditions in television picture transmission via radio channels or facsimile transmission produces markings in columns on a recording strip. In such recordings, the information corresponding to the respective measured value may be contained, in addition to its location in the respective column and the position of the column itself, in the intensity of the markings along each column.

The present invention is initially based on the realization that the conventional rigid coupling existing between the sequence of the measured value registration and the sequence of the measured value processing and display or recording in such conventional recording devices constitutes an unnecessary limitation on the degrees of freedom for the evaluation of the information. The invention is based on the further realization that in order to concentrate on the data actually of interest at a given moment be they certain measured values from a sequence of measured values, the entire sequence of measured values within a selected partial section of the measuring range, the switching of the measuring range or an association between measured values and other informations, variations between linear and nonlinear scales or the like this rigid coupling would have to be eliminated. However, in order to provide a satisfactory solution to the problem of eliminating this rigid coupling, consideration has to be given to the fact that the solution would have to be a method and/or an apparatus for performing this method, which could be freely adapted with the least amount of circuitry or an amount of circuitry which would be justifiable in each particular case, and which would meet the special technical requirements of each SUMMARY OF THE INVENTION This is accomplished according to the present invention with a method of the above-mentioned type in 0 which a measuring period and the process of displaying and/or recording (hereinafter uniformly called the display period) occur independent of one another. The independent variable of the measuring period is quantized and a position identifying value assigned to the resulting measuring sections and a given display range, for example the length of the columns transverse to the longitudinal direction of a recording strip, is quantized and a location value associated to the resulting display sections. The quantized measured values of the measuring periods, which had been started at a point which is arbitrary with respect to the momentary conditions of the display period, if required, after selection according to given criteria and with the use of characteristic quality, denominators for each newly stored information as well as for the previously stored information (quantized measured value and if required additional information) are written into a memory circuit, utilizing the position indicating values as address parameters. Finally during a display period which has been arbitrarily started with respect to the momentary conditions of the measuring period, the information momentarily stored in the memory circuit, and which is possibly provided with a given quality criterion, is consecutively read out for each location value which is unequivocally associated with each position indicating or address value and displayed, for example by means of recording in columns on a recording strip. The reading out of the information takes place with a preferably constant but variable read-out pulse frequency which is of a preferably substantially smaller order of magnitude than the previously employed freely variable write-in pulse frequency.

It is known in principle from the measuring and data art to save on memory or transmission means requirements with respect to the information to be evaluated by processing the information signals to provide a suitable data reduction even before the signals are stored. It is also known, for example, from the tape storage art, to influence the relative movement between the magnetic head and the storage tape by moving the magnetic head (e.g., a rotating magnetic head in video tape recorders, or a displaceable magnetic head, for example, during the accompaniment of solo performers by means of recorded orchestral music) and to thus possibly vary within certain limits the time association between the write-in and the read-out process. However, the above mentioned combination according to the present invention of known individual features within the scope of the problems at hand leads to a freedom of movement between measured value determination and measured value reproduction which has heretofore not been possible in the art in that an apparatus for performing the method of the invention which considers the given condition as to what type of information is to be written into the memory circuit is simply connected between the arrangement for compiling the measured values and the arrangement for reproducing them.

It is now a significant feature with respect to the possibilities of application for this method that, because of the decoupling between measured value determination and reproduction the writing into the memory circuit can occur at a timing which is entirely independent of that used for reading out of the memory circuit with respect to frequency and synchronization. This also makes the recording of the measured values and their evaluation entirely independent of one another. This property is of particular interest when, for example, the measured values are recorded with electronic means but are played back with mechanical means, which is the case, for example, for the paper recording of a facsimile transmission or of an echogram, or generally when the graphic display is to be presented with electromechanical means, such as an echograph, for the typical course of a process which has previously taken place several times but always for very short and perhaps not always strictly identical intervals, and is to be expanded over a wide range but must nevertheless adhere to the finite, given speeds of movement of the mechanical members of the recording device. The method according to the present invention provides further considerable advantages when it is intended to provide continuous and discontinuous evaluation of the measured values in parallel, e.g. the display on an echograph and storage of the informations on punched tapes.

With the present state of the electronic computer art and particularly in view of the universal use of process computers in industry it would be possible, in principle, to have the above-mentioned typical applications of the present invention, as well as those to be described in detail later on, performed by such computer systems by providing them with the appropriate programming. However, the amount of apparatus required for this purpose would be greatly larger and beyond comparison with that required for apparatus for accomplishing the method of the present invention, in addition to the fact that in the typical cases of application to be discussed below the use of complete computer systems would usually be prohibitive for other reasons, such as economical considerations.

Regarding the required circuitry and regarding the possibilities for information processing, the use of the method according to the present invention or of the apparatus for performing this method, respectively, quite substantially increases the freedom of movement with comparatively permissible increased expenditures for the processing of the measured values, since the writein timing and read-out timing of the memory circuit are now practically independent of one another, so that their start, inter alia, can be triggered independent of one another. Particularly favorable effects can be produced if, as will be discussed in detail in connection with certain embodiments, write-in timing and read-out timing are temporarily or continuously oppositely directed or exhibit a relationship which can be varied during operation.

Interesting technical and economical possibilities are also provided by this invention for the entire field of the data transmission art where, according to another feature of the invention, the information is compressed to its significant contents according to given criteria, such as regarding a comparison of consecutive similar informations with one another. Thus in the line-by-line transmission of pictures over radio channels or in the facsimile transmission, a new measured value with the associated address which indicates the respective point of recording need be written into the memory circuit for adjacent sections of each column and/or at comparable sections of adjacent columns only when the degree of blackening or some other criterion substantially changes with respect to the information already at hand, and consequently only such a measured value requires an additional storage location in the memory. All the other picture regions in which no change has taken place compared to the previous states furnish no new measured values so that the information transmission can be limited to a relatively small number of criteria which actually have an information content. For purposes of reconstruction at the receiving end the unchanged, old (already present in the memory) informations are combined with the changed new informations with the aid of an unequivocal given address scheme which constitutes another feature of the invention.

A useful application of this solution in the sounding art leads to novel and promising possibilities for the suppression or cancellation of permanent echoes by simple circuit means. This problem has thus far been solved generally only at great expense, for example with criteria depending on the relative speed, i.e. by means of evaluation of the Doppler effect, since for purposes of commercial navigation a computer of the type employed by flight monitoring centers can generally not be seriously considered for economic reasons. The possibilities offered by the present invention are of particular interest for the deep-sea fishing industry in which the use of the present invention in conjunction with known fish sounding systems leads to the suppression of the relatively uniformly reoccurring bottom echo in comparison with the weak and continuously changing fish echo which, however, is the echo of interest.

With just as much advantage the present invention can solve the reversed technical problem, i.e. the suppression of all measured values having accidental characteristics, by a comparison of two or a plurality of consecutive comparable measured values. In the picture transmission art, and also in the panorama or partial panorama display in the sounding art, noise influences or sporadic erroneous measurements can thus be eliminated from the final signal processed for display resulting in a recording of the information actually of interest in sharp outlines and without interruptions. Moreover such a recording can now be obtained without correlation processes which require a large amount of circuitry or other signal influences on the processing of the measured values. An appropriate case of application in the field of hydrographic surveying will be described in detail below. Here, and in other cases, substantial automatization previously failed in practice, inter alia, because the required measures for sufficient suppression of the multitude of occurring interferences became too expensive when compared to the total installation. The present invention also places a practicable solution of this problem into a substantially more approachable range.

The method according to the present invention has particular significance in its practical application with the relatively new technique of forming monolithic ring-type closed shift registers since such shift registers can be employed in the apparatus for performing this method as economical and unproblematical memory circuits whose capacity can be dimensioned practically at will.

Numerous other developments and modifications of the basic concept of the present invention which result in effects which thus far could not be realized at all or could be realized only with substantially much greater expenditures can be employed in other fields than those specifically mentioned above. Only a few of the most interesting examples will be discussed in detail below within the description of a drawing, the present invention first being discussed with the aid of a basic data flow diagram. The apparatus embodiments for performing this method which then follow relate first of all to applications in connection with the sounding art and particularly the echo sounding art without the selection of the embodiments here specifically presented being considered to constitute a limitation of the present invention to these particular cases of application.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic data flow diagram representation illustrating the method of the present invention.

FIG. 2 is a block circuit diagram showing a concrete embodiment for the application of the method of the present invention in conjunction with echo sounding in the measuring of depths of bodies of water and in the fishing industry where a towed net is employed.

FIG. 2a is a schematic diagram of one possible embodiment of the drive mechanism for the recording device of FIG. 2.

FIG. 2b is a schematic diagram of an alternative embodiment of the drive mechanism for the recorder of FIG. 2.

FIG. 3 is a detailed block circuit diagram of the information processing arrangement comprising a memory circuit in conjunction with peripheral devices, for the embodiment of FIG. 2.

FIG. 4a is an example in the form of a table illustrating the separation of the display into partial sections.

FIG. 4b is a numerical example for the area control in dependence on the measured values with a division according to FIG. 4a.

FIG. 5 is a schematic block diagram of a circuit for the selection of the display sections according to FIG. 4a and for the logic linkages according to FIGS. 4a and 4b.

FIG. 6 shows a recording made according to the invention on the recording strip as an example of the effect of selection of preferred regions for the entire display.

FIG. 7 is a block circuit diagram of an embodiment of the present invention which requires very little circuitry for the present invention in the form of an economically priced supplemental instrument for use with conventional depth Sounders in shallow water areas.

FIG. 8 is a block diagram ofa modification of FIGS. 2 and 3 for controlling the data input gate to the recorder.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic basic diagram illustrating the operation of the method according to the present invention and simultaneously serves, by means of block circuit diagrams, to introduce and explain a preferred circuit embodiment for performing the present invention.

As schematically indicated in the upper left hand corner of FIG. I, each measuring period Lm is divided into a plurality of measuring intervals lm each of which is associated with a respective position identifying value or marker Mi where i equals a number from zero to p, i.e. M0 to Mp. In each measuring interval Im, a measured value mi, e.g. an amplitude or phase information or value representative of a physical value, is determined. If the measuring processes involve the measurement of an independent variable P over time t, the measuring intervals lm represent time intervals. If the independent variable P of a measuring period Lm is, for example, the location s, or a linear unit, the measuring intervals lm are linear, then the position identifying values or markers Mi identify, for example, various distance measurements. After expiration of each measuring period Lm a new measuring period Lm+1, Lm+2 etc. takes place.

In order to be able to separate sporadic erroneous statistical measurements with a suitable comparison circuit, the measuring conditions are preferably so selected under substantially known conditions, for example, by sufficiently small quantizing of the measuring period Lm or by the repetition density of the measuring periods Lm that for comparable measurements between each two measured values mi and mi+l or measuring periods Lm and Lm+l within the limits of a certain tolerance range to l, the same measured values mi for two consecutive measured values mi and mi+l or corresponding measured values mi of consecutive measuring periods Lm and Lm+l can be expected.

Each individual measured value mi associated to a measuring interval 1m and thus to a position identifying value or marker Mi is written into a memory circuit 1 1, if required after quantization in an analog/digital converter 10. The writing in occurs at a writing pulse timing or frequency Te which is preferably the clock pulse output from a clock pulse generator 12 which also controls, for example, a scanner 13 for the successive processing of the measured values mi in the analog/digital converter 10. Thus this writing pulse timing Te particularly serves to determine the measuring intervals 1m with their associated measured values mi 1 and perhaps also additional information Zi. The total of the measured values mi associated to one measuring interval lm and of the additional information Zi (for which examples will be given later on will hereinafter be simply called the information. The path of the information is shown in the block circuit diagrams of the drawings by a double arrow.

After passage of one measuring period Lm, i.e. after the last measuring interval lm with the position identifying value Mp has been reached, a new measuring period Lm+l is initiated.

The respective position identifying values Mi can be simply provided by the momentary position of a counter 14 which is started anew with each measuring period Lm independent of whether or not the duration of the measuring period Lm is given by a fixed number of measuring intervals lm (as assumed in the upper left of FIG. 1) so that the scanner 13 can be switched to a new measuring period Lm+when the write-in pulse frequency Te has been counted out and position identifying value Mp has been reached, or whether or not the length of each measuring period Lm, and thus the number of its measuring intervals lm, is determined by the conditions of the measuring location or other separately acting control values.

FIG. 1 furthermore shows the example of a write-in pulse frequency Te which remains constant during each measuring period Lm, i.e. where there are equidistant measuring intervals lm. The advantages of a variation in the write-in pulse frequency Te will be discussed later.

Each information stored in memory circuit 11 has associated with it an address Ai which advisably is the position identifying value Mi associated with a measured value mi or corresponds thereto in a given relationship. However, in order to reduce the required circuitry and storage capacity, before a new measured value mi+l is written into a free location in memory circuit 11, it is compared in a comparator 15 with the most recent corresponding measured value mi which has already been stored in memory circuit 11. The latter may be that value, for example, which has been determined in this new measuring period Lm+l, but in the preceding measuring interval lm-l, and the comparison may be limited, in the event different characteristics are determined and stored for each measured value mi, to the characteristic of interest in the present case, e.g., amplitude only or fundamental carrier frequency only, for measured values mi to be compared.

If it is determined in the comparator 15 that, within the limits of a given tolerance range (tol) an old measured value mi in memory 11 and the new measured value mi+1 to be compared therewith coincide, the new measured value mi+1 is written into memory 11 in place of the old measured value mi at the same time an identity or comparison value signal [I which is provided for each individual location in memory 11 is upgraded by one unit. Depending on the definition of upgrading, the comparison value signal II is, for example, increased or decreased in its numerical value. The upgrading of the comparison value signal II is an indication of the fact that this particular location now contains a measured value mi+l which was confirmed, regarding given tolerance criteria, from a measured value mi of older origin with which it was compared. The next following comparison is now based on the stored information or its component which is relevant for the particular comparison, respectively, i.e. the given tolerance region tol slides along with fluctuating measured values mi which are still considered applicable.

When such a confirmation does not occur during a comparison in comparator 15, it is advisable not to erase the previous measured value mi but rather to write the new measured value mi+l into some other momentarily empty location in the memory and to provide it at the same time with the identity value I! of the lowest order of value, i.e. the identity minimum llmin, as a sign that this memory location now momentarily contains some sort of entirely new, unconfirmed measured value mi.

Before further new measured values mi from a successive measuring period Lm-l-Z arrive, the entire contents of memory 11 is cleansed in that the identity values ll of all the memory locations which did not obtain an upgrading of their identity characteristic [1 during the last measuring period Lm+l, are downgraded by one unit. Memory locations with a minimum identity value llmin for older measured values mi, which had not been confirmed several times in a row and which thus continuously had their identity value ll downgraded so that it can no longer be downgraded any further, are thus simultaneously erased.

Since the present invention continuously eliminates older and rarely occurring measured values mi, or measured values that were not confirmed in a sequence of sufficient length by means of the criterion of the identity characteristics 11, care is taken that only good information (good in the sense of the comparison criterion affirmed by the momentary identity characteristic [1) can occupy memory locations. A sufficient number of free memory locations is generally available for new, not previously encountered, measured values mi so that these new measured values mi can be available in the respective following measuring periods Lm+l for the above-described comparison with the preceding measuring period Lm.

A typical embodiment will be described and explained with the aid of a detailed block circuit diagram in connection with FIG. 3 for a circuit arrangement and the required control circuits 16, 16a to perform this selection process in cooperation with the write-in access arrangement 17 and read-out access arrangement 18 at memory 11.

Completely independent in time of the previously described compilation, storage and evaluation of measured values mi of each measuring period Lm is the display of measured values mi according to the present invention within each display range Ld or each reproduction period Td. The reproduction of the conditions during measuring periods Lm may occur, by means of a recording device 19 on a recording strip 20 in the form of markings corresponding to the measured values mi as they are read out of memory 11. For example, as will be explained in detail in connection with FIG. 2, these measured values mi may be displayed on recording strip 20, in this case also recorded simultaneously, with the known configuration of an echograph, one below the other in columns 21 for each measuring period Lm and in adjacent columns 21 for consecutive measuring periods Lm, Lm+l. The length of each column 21 is the display range Ld. A suitable marking implement 22, e.g., a writing stylus in the illustrated case, is employed to produce the markings. The marker 22 traverses the entire length of column 21 once during each display period Td and the informations are contained in the respective position of each marking and possibly also in its intensity. The display range Ld, i.e. the useful width of recording strip 20 and thus the length of columns 21, is divided into preferably equidistant display sections Id. Each one of these display sections Id has a consecutive location number or value Dk associated with it where k equals a number from zero to q, i.e. Dk varies from DO-Dq. A location pulse generator 24 is coupled to the movement of marking implement 22. The respective result of the count of location pulses Id in a location counter 25 which starts counting anew with each display interval Td indicates the momentary position of marking implement 22 within the display range Ld.

The repetition frequency of the location pulses Id determines the read-out pulse frequency or timing of read-out pulses Ta for the information available in memory 11. In a preferred application of the present invention, this read-out pulse frequency has a substantially lower frequency than the frequency of write-in pulses Te. Thus it is assured that for measuring periods Lm which are not extremely long, the same memory location will not be read out twice without at least one new measuring period Lm+l having passed in the meantime and perhaps a new measured value mi+l for each display section Id has been made available upon comparison of its identity or an already present value has been confirmed. 7 In one embodiment of the present invention the frequency of the read-out pulses Ta is advantageously selected, when compared to the frequency of the writein pulses Te, to be so long that a plurality of measuring periods Lm pass during each display period Td and consequently a plurality of comparisons can take place between two associated measured values mi and mi-H. If care is taken that only such measured values mi which have been confirmed sufficiently often, i.e. only such values having an optimum comparison value Ilopt (a value which can no longer be upgraded during renewed confirmation) are read out of memory 11, it is assured with great probability that accidental or erroneous measuring results among the measured values mi will not be displayed at all.

In the simplest case of realizing such circuitry, that information is read out of memory 11, for the case p=q, for each display location number Dk of display range Ld, which is provided with the same measuring position identifying value Mi of one measuring period Lm or with a corresponding address Ai if a sufficiently often confirmed measured value mi, i.e. a measured value with the optimum identity value llopt is present. A useful measuring result for a defined measuring interval lm in a measuring period Lm is thus displayed in a defined, associated display section Id of the display range Ld.

This association or comparison between the measuring position identifying values Mi or addresses Ai and display location number Dk are accomplished by a digital translator 26 which reads the associated information out of memory 11 for each position of marker 22, i.e. for each display location number Dk, and switches it, if an identity control circuit 27 furnishes a positive result with respect to the comparison value Il if necessary via a digital/analog converter 28 to marking implement 22 as a good measured value rm to be displayed.

The removal of the coupling between measured value input and reproduction in the present invention permits such advantageous variations of the scale of reproduction simply by the appropriate variation of the ratio of the frequency of the write-in pulses Te at pulse generator 12 to that of the read-out pulses Ta, i.e. without any kind of changes in the circuitry of the translator 26 or in the function of recording device 19, and with the use of only one translator 26. The limit of applicability in practice for these possibilities lies only and alone in the reasonable relationship between obtainable resolution and desired measuring range. Aside from the advantage of a uniform translator 26, this further development, where, for example, only the control pulse Ts is influenced, exhibits the further advantage that the quantization of the measuring range Lrn can be adapted right from the beginning to the selected scale since only the number of intervals lm that can be displayed in one column 21 are formed so that the memory capacity is limited to the minimum required size.

Whereas in the previously described embodiments the translator 26 took care that the entire content of memory 11, insofar as concerns informations having the optimum identity values llopt, was directly displayed, so that each measuring interval lm was proportionally associated to one display section Id and thus a linear, true-to-scale reproduction of the conditions of measuring periods Lm was recorded over the entire display range Ld, the method of the present invention is also very advantageous if only such informations which are associated to certain measuring position identifying values Mi are recorded either alone or additionally in parallel and either over the entire display range Ld or only over a certain selected portion thereof.

Such problems are encountered, for example, in slave indications regarding certain criteria, for example when different types of observations are to be made for a series of measured values mi and only measured values mi, for example, from the last third of the entire measuring period Lm are to be displayed preferably at an enlarged scale extending over the entire available display range Ld and/or measured values mi from a selected portion of the measuring period Lm are to be recorded in only a partial region of the display range Ld in an expanded manner while perhaps simultaneously recording different informations for example, manual notations or additional informations Zi in the remaining portion of the display range Ld, e.g. at the head of columns 21. For these supplemental additional possibilities, appropriately designed translators 26 are required when the frequency of write-in pulses Te is not influenced. In the embodiment of FIG. 1, these possibilities are realized by the additional translator 26a for reading out the entire contents of memory 11 and writing it into the lower half of recording strip 20 and by the additional translator 26b for the association of the second half of measuring position location values Mi with the totality of all display location values Dk of the given display range Ld. The problem of operating a plurality of conventional recording devices 19 in parallel for recording the results from one and the same measuring period Lm, can be considered to be solved only with the present invention for many practical applications in which due to intermediate storage of the information, stylus marker 22 may have any possible position, entirely independent of the momentary conditions of measuring period Lm. Each individual recording device 19 now produces or displays information independent of the momentary operating state of other recording devices through a translator 26, which information is present in memory 11 corresponding to the momentary position of its respective stylus marker 22. The resulting, very important degree of freedom with respect to measuring value input and reproduction was heretofore not readily or economically available. Accordingly it was generally impossible to obtain synchronism for a plurality of echographs and to operate with parallel-connected electromechanical recording devices, since the expenditures involved were not justifiable in the practice of the user of such systems.

In order not to show a plurality of recording devices 19, such different possibilities are considered in FIG. 1 by a selector switch 29 with which the user of an apparatus according to the present invention can select the type of display he desires utilizing only a single recording device.

With such an arrangement, i.e. when translators 26a and 26b are utilized, informations in memory 11 whose addresses Ai or measuring position location values Mi have no associated display location value Dk for translator 26a and any display section Id of display period Td whose display location value Dk has no associated addresses Ai for translator 26b are not considered during read-out of the information or during recording or display of the information. The limits of practical applicability of this possibility are set in the case of translator 260 by the consideration of whether or not too many details of the succession of measured values mi from one measuring period Lm or consecutive measuring periods Lm will be lost if only a small number thereof are displayed close together in a crowded area, and are set in the case of translator 26b in that with columntype recording of measured values mi in varying degrees of blackening or by a curve consisting of sequences of dots, no clear diagrammatic display results when only a small number of measured values mi are distributed at correspondingly large spacings from one another over relatively long columns 21. When the use of such an expanded display is expected to occur too often, it is advisable to divide the measuring period Lm into a larger number of measuring intervals lm which is much larger than the number of display sections Id provided so that even in the last-considered case, a dense sequence of measured values mi can still be obtained.

In order to freely change the display area within display range Ld, it is only necessary to make changes in the circuitry of the digital translator 26 or regarding the clock pulse frequency at the input of counter 14, which can be programmed, for example for the display scales of interest, and which can be selected by switches. This switching may even be controlled by the measuring result itself since all that is involved is a variation in the linkage of the digital decoding matrix or in another case, a variation of a control parameter for the trigger ing or the natural frequency of the clock pulse generator 12.

Such a possibility of switching the measuring range is of particular interest with recording devices 19 which have mechanically movable parts such as echographs with a stylus band writer or a stylus arm writer. As much as these devices have been modified during the past decades of practical use, the kinetic conditions still remain the most significant source of errors or malfunctions with respect to their long lifetime and precision, particularly in view of the rough environmental conditions and continued operation without much maintenance as is encountered, for example, when used on deep-sea fishing expeditions.

In addition to this above-mentioned weakness of such mechanical recording devices, additional limiting conditions must also be considered. Stylus speeds which are too slow reduce the recognizability of the recording on the recording strip 20, for example, because of too much burning of the spark recording paper, whereas fast stylus speeds produce the annoyance of rapid wear of the writing stylus, i.e. of marker 22... Additionally, with regard to the drive means for the stylus, considerable expenditures are required for motor controls and reduction gears, and in the embodiments of conventional echographs employed in practice the useful variation of the stylus speed lies between about 1:2 and l:8 so that only a relatively small number of scales can be produced because of the given speed of propagation of sound in water. According to experience, the highest scale range realizable is only in the order of magnitude of about 1:100, with justifiable wear of the stylus. The longknown method of avoiding this limitation by arranging a plurality of individual styli closely adjacent one another in the manner of a comb and controlling them consecutively or in any desired sequence by means of electrical means has not been accepted in practice, probably, inter alia, because the realizable resolution naturally depends on the number of adjacently disposed writing styli, which number is limited with a given display range Ld and given writing voltages because of the spacing required to protect against sparkover, and because of the quite obvious drawback in practice that the individual styli wear out to different degrees.

Practically all such problems and drawbacks inherent in conventional echographs are eliminated when an apparatus is employed for performing the method according to the present invention which apparatus is connected between the measured value determining arrangement and the measured value display. For example, in the echo sounding art, the apparatus according to the invention is connected between the input amplifier or possibly the selection circuit for received echo signals and the control of the echograph. The use of apparatus according to the present invention here permits a free variation of the display possibilities as it has not been possible previously. The method and apparatus according to the invention additionally makes it possible to realize special effects utilizing constant speed mechanisms for the recording devices 19 simply by switching relatively uncomplicated circuits constructed of standardized circuits from the digital art, particularly in translator 26 or in connection with clock pulse generator 12.

By means of the translator 26c, another advantageous possibility for varying the selection of display of the measured values mi is indicated, which had no chance of a practically applicable realization with previous systems utilizing mechanical recording devices. In the translator 260 the measuring position location values Mi are logarithmically associated with the display position values Dk. With a system utilizing such a translator 260, although the measured values are recorded during the measuring period Lm and are processed up to memory 11 linearly in time, and although the mechanically and dynamically simplest manner is maintained for the marker 22 which is moved at constant speed across display range Ld for the displaying process, the association between logarithmically increasing numbers of measuring position values Mi or addresses Ai and further linearly increasing display location values Dk results in a logarithmic scale in the display of measured values mi on recording strip 20. Such a display provides the known advantages of a measuring accuracy which is uniform over the entire measuring range under consideration and with constant resolution and optimum utilization of the display range Ld.

Such freely selectable and dimensionable associations are made possible with the method according to the present invention in that the processes of determining the measured values mi and their display take place entirely independent of one another.

The above-mentioned digital operations to be employed in performing the method of the present invention, such as quantization, comparison, clock pulse generation and division, counting, switching and data transfer in dependence on logic conditions and the like, are common problems in present-day digital eletronic systems which are realized increasingly schematically by means of standardized modules of the integrated circuit art. Accordingly the structural configuration of the present invention not only exhibits the advantage that it can be economically produced from mass-produced basic units in spite of the complex individual functions involved, but also it can quickly be dimensioned for the given requirements of a special application, and experience has shown that it will then dependably operate without any further circuit engineering work.

The circuit arrangements and auxiliary displays shown from FIG. 2 on relate even more strongly than the preceding portion of the specification to special but typical cases of application for the method of the present invention. They are intended to show more precisely the advantageous possibilities of the method of the present invention and simultaneously indicate useful and advantageous modifications and variations of the present invention without limiting the significance of the present invention to these applications.

In the following selected embodiments of the invention, reference is always made to applications in the reflected beam sounding art, particularly in the echo sounding ranging art for navigational purposes, surveying and fishing, i.e. for surveying the depth of bodies of water and the location of fishing grounds. In the following embodiments for devices for performing the method of the present invention there are shown, in addition to the above-mentioned arrangement for comparison of a measured value mi with a comparable older measured value mi-l, other devices which are particularly advantageous in connection with the present invention for reducing the compiled data to the information of interest, in the interest of maintaining the capacity of memory 11 within acceptable limitations. Moreover, further applications of useful variations are explained in view of the purposes selected in the particular example.

Aside from the special characteristic of the information processing component 30 which will be specified in detail in FIG. 3, the combination of the devices shown in FIG. 2 substantially corresponds to that of a conventional echo sounding device, for. example, for determining the profile of the bottom 31 of a body of water 32 or for location of fish 33 and for determining the depth of a towed fishing net 34.

The advantageous use of apparatus according to the present invention for measuring depths will first be considered. The measuring path 36 to be determined is disposed between a transducer 35 and the bottom 31 of the body of water 32 in FIG. 2. The measuring period Lm of FIG. 1 corresponds to this measuring path 36 and is initiated by the transmittal of a pulse signal se by the transducer 35. Upon return of the transmitted signal Se and reception as a bottom echo signal Be of interest from bottom 31, a measuring period Lm is completed and a new measuring period I..m+l can be begun, for example at the same location. Preferably, however, the new measuring period is begun at a location offset with respect to the location of the preceding momentary measurement by a certain amount in that the surveying vehicle 37, which is the carrier of the surveying system, is moved.

The display of the measured values mi, i.e., of the measuring result of the length of the measured path 36 and thus of the momentary depth of body of water 32, is accomplished in the embodiment of FIG. 2 on a conventional echograph 38 (see the recording device 19 of FIG. 1) by means of a writing stylus 40 (see marking implement 22 of FIG. 1) which is fastened to a rotating stylus band 39. The stylus 40, in a known manner leaves a succession of markings 42 in response to a writing voltage applied via a contact rail 41 on a recording strip 20, e.g. on electrically sensitive paper by spark traces.

The recording strip 20 is moved in a known manner, which is not shown in detail in FIG. 2. For example, the strip 20 may be moved at a continuous, slow speed by means of a continuously active forward movement drive or discontinuously by the stylus 40 after it has passed over the entire width of the recording strip 20 via a follower mechanism in dependence on the rotation of the stylus 40. In the case of the embodiment shown in FIG. 2a the stylus band 39 is continuously driven by an advance motor 43 as the drive mechanism 50, if required via a step-down gear 51, whereas in the case of the embodiment of FIG. 2b a stepping motor 52 effects a discontinuous drive of the stylus band 39 in steps of a suitably fine graduation. While a direct speed control is practically impossible with extremely slow moving d.c. drives, the selection of the stepping motor 52 illustrates the advantage that, according to the invention, it is possible to realize, without mechanical reduction gears and simply by a control of the location pulse generator 24, any desired slow rotary movement in defined small steps which may be necessary, for example, for the display of the measured values mi of a very long measuring path 36.

Further advantages of the selection of the stepping motor 52 as the drive for the writing stylus 40 will become evident in connection with FIG. 3. A recording device 19 with a writing stylus 40 on a stylus band 39 or on a pivot gear are selected here as examples only for reasons of simplicity. Moreover, marking implement 22 in the form of a writing helix on a rotatably mounted roller or, in other applications, a punch pattern cutter or the writing head of a magnetic storage device serve similar purposes in a known manner for displaying or recording of measured values mi and should be considered' equivalent in connection with the present invention.

The measured values mi in this first case of application under consideration are assumed to be the amplitudes during echo sounding at defined points in time (beginning with the transmission of a signal Se at the starting point mo in FIG. 1) and thus bottom echo signals Be received with defined momentary measuring position location values Mi. The additional informations Zi may be informations relating to the measured values mi of interest about the location of the measurement, for example, with reference to the kilometer along a stream or channel and/or transverse thereto with reference to a fixed point on shore, information about the momentary level of the tide, date or series of measurements and the like, association of received echoes to a certain transmitted signal Se from a group of simultaneously transmitted signals, or the momentary measuring range and measuring scale and the like. Such auxiliary data which might be required for the later evaluation or might be at least useful in connection therewith may be associated to the momentary measured values mi either manually or via special measuring locations. In FIG. 2 this auxiliary data is supplied by means of an auxiliary data input device 53.

Particularly in the depth measurement of bodies of water, the first bottom echo signal Be, i.e. the location of the upper edge of the bottom 31, is of foremost interest and then perhaps also the further arriving bottom echosignals Bel, Be2,... which permit, in a known manner, conclusions about the inner structure of the bottom 31. Earlier appearing echo signals, which may be caused, for example, by fish 33, drifting material or air bubbles, and other interfering signals are filtered out, if possible, by suitable filter circuits 55 connected to the receiving amplifier 54.

If the information contained in the amplitude path and in the length of the bottom echo signals Be is not considered, a requirement which is absolutely sensible for surveying to determine cross-sectional profiles of bodies of water 32, the only measured value mi required from each measuring period Lm for this reduced purpose consists only of the travel time information regarding the time interval between transmission of the signal Se and reception of the bottom echo signals Be. In the illustrated method of FIG. 1, in view of the running time variable utilized to provide the measuring position location values Mi, the momentary value of Mi at the arrival of the bottom echo signal Be constitutes the measured value mi. Only this case will first be discussed in connection with FIG. 3 and in the following description of a first embodiment for the information storage and processing unit 30.

In the circuit arrangement shown in FIG. 3 for an information storage and processing unit 30 for use in a measuring arrangement for the purpose discussed above in connection with FIG. 2, a free running clock pulse generator 12 furnishes the central control pulses Ts for the entire digital information processing. There control pulses Ts simultaneously serve as the write-in pulses Te discussed in connection with FIG. I for memory 11 and to quantize the measuring period Lm into measuring intervals lm. The beginning of a measurement is indicated by means of a start key 56. Closing of the switch 56 causes a transmitter 57 (shown only in FIG. 2) to be triggered to emit, via the transducer 35, a transmitting signal Se, and simultaneously a switch in the information storage and processing unit 30, for example a flipflop 58, which itself switches a gate 59 to be enabled.

In the circuit embodiment now under consideration no use is made of differently dimensioned translators 26 26d as in FIG. 1. Rather the measuring range for the display can be selected by an adjustable pulse frequency divider 60, so that the quantization, i.e. the number of measuring intervals lm per unit time, can be varied with constant quantization of the display range Ld as discussed below. The output pulses at the output of divider 60 represent a reduced frequency of control pulses Ts which are counted during the duration of a measuring period Lm in a depth counter, counter 14 (see FIG. 1). The momentary result of this count within one measuring period Lm represents the respectively reached travel time parameter or measuring position identifying value Mi. For reasons which will be discussed later, the counter 14 is advantageously a combination of a primary counter 61a and a carry counter 61b.

The value Mi present in counter 14 at the moment of the arrival of a bottom echo signal Be is now written via a transfer circuit 62 into a first intermediate memory 63 as the desired measured value mi of the present measuring period Lm. Simultaneously, if required, the intermediate memory 63 is supplied with additional available informations Zi from the data input device 53 which furnishes these in the same manner in a binary code.

With the measuring sequence selector switch 64 set at position a as illustrated, the received bottom echo signal Be also resets flipflop 58 so that gate 59 is again blocked and no further control pulses Te are counted into counter 14. Since the central control pulses Ts are further required for the operation of the measuring value processing (data transfer) in the embodiment here under consideration, the clock pulse generator 12 must not be stopped even in the pause between two measuring periods Lm and Lm-i-l By resetting flipflop 58, a reset pulse Ir is delivered to counter 14 whereupon a new measuring period Lm+lcan be begun, e.g. via start key 56. Position a of the measuring sequence selector switch 64, at which the start of a subsequent measuring period Lm+l does not occur automatically, is used for special or unusual requirements. For example, this position may be used when it is advisable to set the measuring periods Lm individually by hand, for example, for alignment, detecting of errors or calibration of the circuit.

If the measuring sequence selector switch 64 provided in FIG. 3 is switched to position b, then the arrival of the bottom echo signal Be from the receiving amplifier 54 and filter 55 (FIG. 2) resets the flipflop 58 to generate the reset pulse Ir and subsequently enables the flipflop 58 to close gate 59 and thus automatically initiate a new measuring period Lm+l. The enabling of flipflop 58 is preferably accomplished via a delay circuit 65, or another suitable blocking circuit dependent upon the momentary measured value mi so that subsequently appearing multiple echoes Be of transmitted signals Se which have passed over the measuring path 36 several times cannot interfere with the subsequent measurement. The measuring sequence and thus the length of the respective measuring period Lm is thus adapted to the momentary conditions of measuring path 36. Protection against multiple echoes He can also or additionally be incorporated in a known manner in filter circuit 55 (FIG. 2).

In position of the measuring sequence selector switch 64, the circuit is so designed that the measuring period Lm always has a constant length. In this position the counter 14 is not stopped immediately upon the arrival of the first bottom echo signal Be (this counter now effects only the transfer of data for a momentarily available counter result by means of transfer circuit 62) but rather it continues to receive pulses Ts from the control clock pulse generator 12 until it reaches a given counting level, for example the maximum value of its counting capacity. Only a transfer pulse Ice 1 appearing at this time resets flipflop 58 via this switch position c and thus terminates measuring periods Lm. This mode of operation has different advantages in its practical application. For example, it may be possible that in spite of filter circuit 55 an erroneous pulse inadvertently acts as a presumed bottom echo pulse Be on the information processing unit 30 whereas the true bottom echo signal Be would appear much later. Since the measuring period Lm in position c of switch 64 is now not terminated immediately after the first arriving pulse, both arriving measured values mi (in the present case as running variables Mi) are transferred consecutively to the first intermediate memory 63. In the course of the comparison of the measured values and under consideration of the comparison values II discussed in connection with FIG. 1, only the true measured value mi of the actual bottom echo signal Be will be displayed because only this signal will be repeatedly confirmed in consecutive measuring periods Lm which will be discussed in detail below.

A further practical significance of position c of the measuring sequence selector switch 64 can be seen in that, as already mentioned, when surveying bodies of water, bottom layer formations at the bottom 31 of a body of water 32 are often of interest in addition to the momentary depth (in FIG. 2 the measuring path 36), which bottom layer formations lead to successively arriving bottom echo signals Be 1, Be 2, In position cit is thus possible in addition to the first original bottom echo signal Be from the bottom 31, to compile and evaluate those further arriving bottom echo signals Be 1, Be 2, which occur before counter 14 has reached its set maximum value and has terminated the present measuring period Lm by means of the transfer pulse Icc 1.

With unfavorable reflection conditions at the bottom 31 it may occur in practice that a bottom echo pulse Be does not arrive at all during a sounding period Lm. In order not to have to unnecessarily expand the individual measuring periods Lm and/or not to have to suffer an interruption on the automatic measuring operation, it is advisable to replace position b of the measuring sequence selector switch 64 by a position d in which, in the described exceptional case of unfavorable reflection conditions, the criteria according to position c will still be effective. In position d, the start of a new measuring period Lm+l is initiated by transfer pulse [cc 1 at the latest when the selected maximum value has been reached in counter 14, if it has not been initiated earlier by a bottom echo signal Be. For this purpose an AND logic gate 66 is provided which combines the two criteria according to positions b and c into that according to position d.

The momentary counter position of counter 14 as determined by transfer circuit 62 thus represents measured value mi. When the first intermediate memory 63 has stored this value and perhaps also additional informations Zi associated therewith the information is first advisably transferred by means of suitable intermediate memory controls 67a, 67b (in FIG. 1 these controls were indicated generally by memory circuits 16 and 160) into a second intermediate memory 68 where it is then available to the final memory 11 for comparison operations with comparable older measured values mi and for writing in as soon as a free memory location appears at the write-in access 17.

According to one aspect of the present invention, the memory circuit 11 is itself comprised of closed ringtype shift registers having as many bits as are required for storing of the measured values mi, possibly further additional informations Zi as well as the identity or comparison characteristics II for the memory location and finally further data for the memory control itself. It must also be considered when dimensioning the memory circuit, that a plurality of measured values mi must be stored which will not appear later on when they are not confirmed sufficiently. The expenditures for the dimensioning of the memory 11 depend on the information limitation permissible for each particular case. The specific requirements and individual functions of the intermediate memories 63 and 68 as well as for the controls 67a and 67b for the intermediate memories depend in each case on the type and function of the selected memory circuit 11 and are thus not symptomatic of the present invention.

The shift register constituting memory 11 is rapidly shifted by a write-in control 69 so that all memory locations have passed completely through at least once and usually even several times during the shortest measuring period Lm to be expected. During the shifting, whenever the output of the second intermediate memory 68 is coupled to an unoccupied location in memory 11 via write-in access 17, the information contained in this second intermediate memory 68 is written into the presented unoccupied or free memory location.

During this cycling or shifting of the informations in the shift register, the identity comparison between the new measuring value mi+l appearing at the output of the second intermediate memory 68 and an associated older measuring value mi takes place in a comparator 15. In the case of the embodiment illustrated in FIG. 3, this operation can be accomplished with particularly low expenditures since the only measured values mi being presented for comparison are the measuring position identifying or travel time values Mi which represent the arrival of bottom echo signals Be. The

identity control is defined, in a simple exemplary case, as being successful when during one cycle of all the information in memory 11 an older measured value mi is found which sufficiently coincides with the presently available new measured value mi-l-l.

During cycling of the information in the shift registers a comparator l5, e.g. a simple digital difference circuit, which, in spite of the binary coding of the information, advisably operates in decades for economical reasons, successively forms the absolute difference between the old measured value mi stored in each memory location as it is presented at the readout output 18 and the new measured value mi at the output of the second intermediate memory 68. This identity control is thus considered to be successful per definition, when for any one of the total of memory locations of memory 11 a difference which lies within a tolerance range (tol) selected by a tolerance value generator 70 appears at the output of comparator at any time during such a cycle. In the event of a successful identity comparison, an evaluator 71 determines the momentary comparison identity value II of the respective memory location and upgrades it by one unit unless the identity or comparison optimum signal Ilopt has already been reached which then remains in existence. Advisably the old measured value mi is simultaneously replaced by the new one so that the set tolerance region (tol) always extends uniformly on both sides of the valid measured value mi. A coupling between the tolerance value generator 70 and a selection possibility for the measuring range, e.g. divider 60, effects a constant measuring accuracy.

A new measured value mi which can not be confirmed in this manner by a stored older value is transferred, after one cycle of the memory locations, into the next free memory location and is provided with the lowest possible identity value signal llmin. The memory 11 must therefore be dimensioned large enough to be able to store, in addition to the calculatable number of useful results, measured values mi for which no determination has yet been made as to whether or not they constitute erroneous measurements.

In addition to providing for an upgrading of the comparison or identity value 11, evaluator 71 produces a marker n which may consist of a single bit, in each memory location which has been provided with new information during the present cycle of the informations in memory 11, i.e. each memory location which has either had its comparison value II upgraded or in which new information has been written for the first time. These markers n are utilized to insure that the older measured values mi, i.e. such values which were not confirmed during a plurality of past measuring periods Lm with respect to a newer measured value mi, gradually disappear from the memory circuit 11 for the purpose of providing free memory locations for future measured values mi. These markers n are deleted by a clearing or cleaning circuit 72 in each following cycle of the information in the memory 11, for example at the end of each measuring period Lm or after a single cycle of the stored informations. In the course of this next cycle of the stored informations during which no new measured value mi is present, this clearing circuit 72 causes the evaluator 71 to reduce the comparison value 11 by one unit in each memory location which has not just had its information content changed, and which consequently does not have a marker n. Simultaneously, the existing markers 11 are erased in that the one bit is again removed. If, however, the identity minimum value Ilmin is already present at a memory location without the marker n, the contents of this memory location is now erased completely, i.e., the location is again available to accept new measured values mi from subsequent measuring periods Lm from the second intermediate memory 68. In that latter case, i.e. when the cleaning circuit 72 gets at the same time I l min and no marker n information, it orders the evaluator 71 to erase that memory location completely.

The intermediate memory control circuits 67a and 67b as well as the write in control circuit 69 and also the different possible circuit configurations of, for example, the digital transfer circuit 62, counter 14, comparator l5 and evaluator circuit 71 are not considered to be the object of the present invention or variations of the present invention unless expressly specified to the contrary since their design depends, in each individual case in practice, entirely upon the selection of the digital processing mode (parallel or serial, preferred code, logic testing and control conditions) as well as upon the type of memory circuit 11 employed in each individual case, e.g. core memory or shift register. Such circuits can be obtained from known producers of such digital circuits which in the future will predominantly be of the integrated type already adapted to the respective requirements, unless special features are concerned for which protection is claimed within the scope of the present invention and which will be appropriately mentioned within this specification.

From the above discussion of the signal storing and processing unit 30, it can be seen that the capacity of memory 11 represents a critical value for the performance of the method of the present invention. In order to be able to utilize the memory capacity to its best advantage, the present invention thus introduces the concept of the comparison or identity value characteristic II which can be realized in the digital art with comparatively low expenditures and which, according to further features of the present invention, comprises the additional advantage of eliminating statistically occurring error measurements.

However, unfavorable extreme cases are conceivable in practice in which the conditions of the measuring path 36 lead to so many measured values mi that the capacity of the memory 11 no longer suffices. This occurs, for example, when the surveying vehicle 31 crosses its own screw waters or those of another vessel or when another distinct interference source falls in the measuring path 36. This may also be the case when, with a strongly fluctuating bottom 31 of the body of water 32 and with a respectively unfavorable speed of the surveying vehicle 37, all the compiled measured values mi are different from one another as if each one would be a uniquely occurring error measurement. To eliminate this problem it is possible to increase the tolerance range (tol) by means of the tolerance signal generator 70, and to thus obtain a somewhat more inaccurate measurement in that even with relatively strongly differing measured values mi which of course also may contain actual error measurements the results of the individual measuring periods Lm are considered to be confirmed. Alternatively, the speed of the advance movement of the vessel 37 may be reduced so that measuring paths are covered which lie closer together, and thus the differences between the measured values mi of each two measuring periods are reduced so that the tolerance range (tol) can again be made smaller.

Independent of the conditions of measuring path 36, it may also happen that, with respect to the capacity of the memory 11, which for economical reasons cannot have any desired large dimensions and which should always be optimally utilized, there is an excess of measured values mi when, in position c of the measuring sequence selector switch 64 (FIG. 2), the selection has been made too high, i.e. when, for example, too many bottom echo signals Be 1, Be 2.... or multiple echo signals Be arrive during each measuring interval Im. A further reason may be that the number of steps in the comparison identity value characteristics ll, between llopt and Ilmin, is selected too large so that measured values mi which at one time were good (were provided with llopt) will remain in memory 11 unnecessarily long when they are no longer confirmed and occupy space therein until they have finally fallen to the minimum identity value Ilmin required for erasing.

Considerations regarding optimization showed, for example, that for measured values mi obtained during surveying of bodies of water 32 a graduation between Ilmin zero and llopt three is sufficient. In such a case, evaluator 71 is constructed as a counter according to the so-called Gray code which for forward and backward counting to three exhibits the most favorable conditions regarding the circuitry required therefor.

In order not to have to dimension memory 11 itself excessively large and still not lose too many individual measured values mi, intermediate memories 63 and 68, in addition to respectively transferring measured values mi from the counter 14, which continues to count in position c, and preparing a measured value mi to be processed at the write-in input 17 of memory 11, may also simultaneously be utilized, in cooperation with the intermediate memory control 67a, 67b, to serve as a buffer in the event there is a temporary excess supply of data. 1

Technically more elegant and often required in practice is a further development of the present invention according to which the supply of measured values mi is reduced by an automatically actuated control or regulating circuit when memory 11 is already rather full. It is here advisable to preferably select the momentary amplification factor of the receiving amplifier 54 (FIG. 2) in dependence on the momentary occupation density of memory 11 as the actuation criterion and, according to this dependency, to choke or cut off the supply of new measured values mi, if required, by a reduction in the amplification factor. To realize the solution of this partial problem in circuit means, the number of memory locations which are occupied or unoccupied, the number of memory locations provided with any one of the identity values II or not having this particular identity value, is determined, for example, by a counter 73 (FIG. 3) and the result of this count, which is present in analog or digital form, or a relative value regarding the total number of the available memory locations, is utilized as the control value for the amplification factor of the receiving amplifier 54. Ad-

vantageously any desired known integration and threshold value circuit 74 (FIG. 2) is connected ahead of the amplification influencing means so that the am- 5 plification is influenced over the time integral of the occupation density of memory 11. Preferably the circuitry is selectively so designed that the influence or change in the amplification is actuated, for example, only at a certain given occupation density to initially increase linearly and, with very dense memory location occupation, to increase exponentially or otherwise progressively. With such an arrangement it is assured that with much unused memory capacity many details value one measuring well as that Lm are compiled and processed in the previously described manner, whereas at a momentarily dense memory location occupation increasingly only particularly strong bottom echo signals Be reach the information processing unit 30 so that the resulting measured values mi represent with greater probability the bottom echo signals Be from bottom 31 which are of foremost interest. Thus, the undesired situation that some of a plurality of good measured values are entirely eliminated because the memory 11 is overloaded is substantially avoided. The circuit realizations of integration and threshold valve circuits as realizations of a variable amplification factor with given characteristics are known to the expert in the art and need not be discussed in detail at this time. Instead of automatic influence on the amplification factor of the receiving amplifier 54, it is also possible to actuate the setting manually in dependence on an indication of the density of the momentary memory loca-- tion occupation.

When such a control for the supply of data is available, the above-mentioned possibility of using the intermediate memories 63 and 68 as buffers is not required and they can be utilized exclusively as transfer memories for only a single measured value mi Mi. This results in a particularly simple and economical embodiment since every intermediate memory 63 or 68 then need consist of only so many flipflops as corresponds to the number of bits of the information to be stored.

It can easily be seen from the above explanations of the operation of the write-in side of the information storage and processing unit 30 where, in the interest of compact functional description, only a simple special case for measured value compilation and processing was discussed, that the present invention comprises a number of variations of the above described embodiments, particularly in view of the criteria of the measured values mi to be processed and regarding the information control between the second intermediate memory 68 and the controlling of the write-in process into the memory 11. Thus a comparison value signal I! can still be treated as admissible when the optimum identity value llopt was not required once or was not required for the first time, respectively, so that the previously confirmed measured value mi can continue to be used with a one-time error measurement.

Before discussing advisable and inventive further developments of the previously described circuit for the information processing unit 30, the circuit embodiment shown in the bottom portion of FIG. 3 will be described for the process of displaying with reference to the corresponding illustration in FIG. 2, including 

1. A method for compiling, evaluating, displaying and/or recording, preferably for displaying and/or recording in the form of a columnar arrangement, measured values (mi) obtained during a measuring period (Lm) within a sequence of measuring periods and dependent on a given independent variable (P), wherein the measuring period (Lm) and the displaying and/or recording period (hereinafter uniformly called the display period Td) take place independent of one another, so that the display and/or recording can take place, if required, at another location and at another time than where the measured values were compiled, comprising: quantizing the independent variable (P) of the measuring period (Lm) and associating a measuring position identifying value (Mi, where i 0-p) with each of the resulting measuring intervals (lm); quantizing the measured values (mi) of a measuring period (,Lm) which has been started at any desired point in time with respect to the momentary conditions of a display period (Td); writing the quantized measured values (mi) from each measuring period (Lm) into a memory circuit utilizing the values Mi as memory address values (Ai); quantizing a given display range (Ld) and associating a display location value (DK, where K 0-q) with each of the resulting display sections (ld); establishing a predetermined association between the values Mi and DK; for each consecutive display location value DK occurring during a display period (Td) started at any desired point in time with respect to the momentary conditions of a measuring period (Lm), reading out the information stored in the memory having an identifying value Mi unequivocally associated therewith, said reading-out taking place with a constant read-out timing frequency of a substantially smaller order of magnitude than the freely variable write-in timing frequency employed; and displaying the information read out of the memory in the associated locations of the display range.
 1. A method for compiling, evaluating, displaying and/or recording, preferably for displaying and/or recording in the form of a columnar arrangement, measured values (mi) obtained during a measuring period (Lm) within a sequence of measuring periods and dependent on a given independent variable (P), wherein the measuring period (Lm) and the displaying and/or recording period (hereinafter uniformly called the display period Td) take place independent of one another, so that the display and/or recording can take place, if required, at another location and at another time than where the measured values were compiled, comprising: quantizing the independent variable (P) of the measuring period (Lm) and associating a measuring position identifying value (Mi, where i 0-p) with each of the resulting measuring intervals (lm); quantizing the measured values (mi) of a measuring period (Lm) which has been started at any desired point in time with respect to the momentary conditions of a display period (Td); writing the quantized measured values (mi) from each measuring period (Lm) into a memory circuit utilizing the values Mi as memory address values (Ai); quantizing a given display range (Ld) and associating a display location value (DK, where K 0-q) with each of the resulting display sections (ld); establishing a predetermined association between the values Mi and DK; for each consecutive display location value DK occurring during a display period (Td) started at any desired point in time with respect to the momentary conditions of a measuring period (Lm), reading out the information stored in the memory having an identifying value Mi unequivocally associated therewith, said reading-out taking place with a constant read-out timing frequency of a substantially smaller order of magnitude than the freely variable write-in timing frequency employed; and displaying the information read out of the memory in the associated locations of the display range.
 2. The method of claim 1 wherein said measuring location identifying values are running time values of the measuring period Lm.
 3. Method as defined in claim 2 wherein the write-in timing frequency for the memory circuit is entirely independent of the read-out timing frequency as regards frequency and synchronization, the read-out timing frequency is optimally adapted to the available devices utilized for compiling, evaluating, displaying and/or recording the measured values (mi), while the write-in timing frequency is oriented only to the conditions of the measured value compilation during the measuring periods (Lm).
 4. The method as defined in claim 3 wherein the measuring period (Lm) and the display period (Td) are started independent of one another.
 5. The method as defined in claim 1 wherein the sequence in which the display locations (ld) are available during the display period (Td) is reversed with respect to the sequence of the measuring intervals (lm) during the measuring period (Lm).
 6. The method of claim 1 including the step of generating and recording an indication representative of the quality of the measured value information according to a given criterion stored in each address of the memory.
 7. The method as defined in claim 6 wherein the repetition frequency of a measured value (mi) is used as the quality criterion and including the steps of: comparing each new measured value (mi) before it is written into the memory circuit, with the comparable measured value (mi) stored therein; and, in the event of coincidence within a given tolerance range (tol) between the compared values, changing the value of the indications representative of the quality of the measured value information (hereinafter referred to as the comparison value signal Il) stored in the memory to an upgraded value which, compared to the previously available value, represents, per definition, an improved value.
 8. The method as defined in claim 7 wherein new measured values (mi) which do not coincide, within a given tolerance range (tol), with already stored older measured values (mi) are written into an available free location in the memory and are provided with a minimum comparison value signal (Ilmin).
 9. The method as defined in claim 8 wherein new measured values (mi) are compared with previously recorded measured values (mi) which appeared in the preceding adjacent measuring period (Lm) for the same position identifying values (Mi).
 10. The method as defined in claim 8 wherein new measured values (mi) are compared with previously recorded measured values (mi) which appeared in the same measuring period (Lm) but for the previous Position identifying value (Mi-1).
 11. The method as defined in claim 8 wherein each new measured value (mi) is compared only for coincidence within the given tolerance range (tol) with any measured value (mi) already stored in the memory.
 12. The method as defined in claim 6 wherein, in the event of coincidence, within a given tolerance range (tol) between an older stored measured value (mi) and a newer measured value (mi), in addition to upgrading the comparison value (Il), the older stored measured value (mi) is upgraded by writing the newer measured value in the associated memory address location in place of the older previously stored measured value.
 13. The method as defined in claim 12 wherein stored measured values (mi) which are already associated with a given optimum comparison value (Ilopt) are no longer upgraded when a new confirmation by new measured values (mi) occurs within the given tolerance range (tol).
 14. The method as defined in claim 13 including, during the writing of information into the memory, providing and storing a marker (n) for each memory location in which a measured value (mi) from measuring period (Lm) being processed has been written.
 15. The method as defined in claim 14 wherein, after the measured values (mi) in all of the memory locations of the memory have been tested for comparison with measured values (mi) determined in a measuring period (Lm) and before the initiation of the processing of new measured values from a measuring period (Lm+1): each comparison value (Il) associated with a memory location not provided with a marker (n) is reduced in value by one unit, and all of the information, e.g. measured value (mi) and comparison value (Il), in each memory location which is provided with a comparison value (Il) which corresponds to the minimum comparison value (Ilmin) and does not have a marker (n) is erased so that from now on the respective memory location is available for new measured values (mi), and each of the markers (n) is erased.
 16. The method as defined in claim 7 wherein the new measured value is written into a memory location of the memory when coincidence occurs between an older stored measured value and a new measured value (mi), and measured values (mi) of consecutive measuring periods (Lm) which coincide a predetermined number of times are erased.
 17. The method as defined in claim 7 wherein: during the read out of the memory in a display period (Td), the comparison values (Il) are detected and only measured values (mi) stored in the memory circuit which are associated with a predetermined optimum comparison value (Ilopt) obtained from a sufficient number of repeated confirmations of successively arriving comparable measured values (mi) are read out upon comparison of the values DK and Mi, so that the reading out of a particular measuring value (mi) when the display marker implement has reached that display section (ld) within the display range (Ld) which, with the given display scale, represents a true-to-scale representation of the present measured value (mi) without there existing a direct connection with the preceding process of compiling the measured values.
 18. The method as defined in claim 2 wherein the entire course of the measured values (mi) is quantized over the independent variable (P) for each measuring period (Lm) and the measured values (mi) are written into the memory utilizing the running time values (Mi) as address values.
 19. The method as defined in claim 2 wherein only the portion of the course of the measured values (mi) which is of interest is quantized over the independent variable (P) for each measuring period (Lm) and the measured values (mi) are written into the memory utilizing the running time values (Mi ) as address values, and wherein the running time values defining the beginning and the end of the course portion of interest are simultaneously written into the memory with the associated measured value (mi) as auxiliary data (Zi).
 20. The method as defined in claim 19 wherein only the running time values defining the beginning and end of each succession of measured values (mi) of interest within one measuring period (Lm) are written into the memory.
 21. The method as defined in claim 18 wherein only the running time value (Mi) at the first appearance of a typical event is considered as the applicable measured value (mi) for each measuring period (Lm).
 22. The method as defined in claim 2 wherein in order to provide for a variation of range and/or scale of the display of the measured values (mi) within the display range (Ld), a selectable number of running-time values (Mi) is associated to a selectable number of display location values (DK) which represent the respective available display range (Ld).
 23. The method as defined in claim 22 wherein with a constant quantization of the measuring period (Lm) and of the display period (Td) in scale and/or range the variation is accomplished by varying the association required between the values Mi and DK for read-out and display by means of a switchable digit comparator.
 24. The method as defined in claim 22 wherein the variation in scale and/or measuring range is accomplished by varying the measuring timing frequency, and thus the timing of the quantization of the measuring period (Lm) while maintaining a constant read-out timing frequency, and thus constant quantization of the display range (Ld), and the same association between the values Mi and DK.
 25. The method as defined in claim 22 wherein the measuring timing frequency is not constant during a measuring period (Lm).
 26. The method as defined in claim 25 wherein the measuring timing frequency varies at a logarithmically decreasing frequency.
 27. The method as defined in claim 1 wherein the steps of writing the measured values (mi) into the memory and of reading out the measured value (mi) for reproduction, occur in an alternating sequence, and wherein the reading-out of the measured values (mi) from the memory circuit is rigidly coupled with the reproduction along the display range (Ld).
 28. The method as defined in claim 1 wherein the method is utilized on a surveying vessel for measuring, compiling and reproducing measured values in an echo sounding arrangement, and wherein the quantization density of the measuring period (Lm), i.e. the number of measuring intervals (lm), is varied in a sense opposite to the momentary lifting movement of the surveying vessel.
 29. Apparatus for compiling, evaluating, displaying and/or recording, preferably for displaying and/or recording in the form of a columnar arrangement, measured values (mi) obtained during a measuring period (Lm) within a sequence of measuring periods and dependent on a given independent variable (P), wherein the measuring period (Lm) and the displaying and/or recording period (hereinafter uniformly called the display period Td) take place independent of one another, so that the display and/or recording can take place, if required, at another location and at another time than where the measured values were compiled, comprising: means for quantizing the independent variable (P) of the measuring period (Lm) and providing a running time digital identifying value (Mi, where i 0-p) for each of the resulting measuring intervals (lm); means for quantizing the measured values (mi) of a measuring period (Lm) which has been started at any desired Point in time with respect to the momentary conditions of a display period (Td); means for writing the quantized measured values (mi) from each measuring period (Lm) into a memory circuit utilizing the identifying values Mi as memory address values (Ai); display means; means for quantizing a given display range (Ld) of said display means providing a digital and display location value (DK, where K 0-q) for each of the resulting display sections (ld); means for comparing each consecutive digital display location value DK occurring during a display period (Td) started at any desired point in time with respect to the momentary conditions of a measuring period (Lm); with the identifying values Mi stored in said memory circuit and for providing an output signal whenever a predetermined association exists between a value Dk and the single value Mi corresponding thereto; and read-out means, responsive to the output signals from said means for comparing, for reading out the information stored in the memory location having the memory address corresponding to the just compared digital value Mi and for transmitting the read-out information to said display means for display in the associated display location (ld).
 30. The apparatus as defined in claim 29 including a control clock pulse generator; and wherein said memory circuit comprises a closed ring-type shift register having a number of shift stages at least equal to the maximum number of identifying values (Mi) i.e., the number of measuring intervals (lm) occurring within one measuring period (Lm), the timing of said shift register being controlled by the clock pulses from said clock pulse generator.
 31. The apparatus as defined in claim 30 wherein said display means includes drive means for moving the marking means of said display means in a uniform manner over the display range in the direction of the recording of the measured values (mi) of a measuring period (Lm); and wherein said means for quantizing a given display range includes means for emitting a series of display location pulses (Id) whose number corresponds to the momentary position of said marking means within said display range, and a digital counter for counting said display location pulses and whose count represents the display location values DK.
 32. The apparatus as defined in claim 31 wherein said display means is a conventional recorder having drive means mechanically coupled to a writing stylus which serves as said marking means, said stylus being coupled to said means for emitting a series of display location pulses.
 33. The apparatus defined in claim 32 wherein said drive means for said writing stylus is a motor which when actuated advances said stylus in a continuous manner over said display range; and wherein said means for emitting a series of display location pulses comprises a pulse disc connected to the motor shaft for rotation therewith and a stationary pick-off.
 34. The apparatus as defined in claim 32 wherein said means for emitting a series of display location pulses is an electronic location pulse generator; and wherein said drive means for said writing stylus is a stepping motor, said stepping motor being excited by the output pulses of said location pulse generator.
 35. The apparatus as defined in claim 31, including a freely running clock pulse generator for providing a series of central control clock pulses said control clock pulses simultaneously determining the write-in timing for said memory circuit and effecting the quantization of the measuring period (Lm).
 36. The apparatus as defined in claim 35 wherein said freely running clock pulse generator provides said central control clock pulses at a constant repetition frequency; wherein said means for quantizing the independent variable of the measuring period (Lm) includes a second digitAl counter responsive to said central control clock pulses for counting same to provide said values Mi and means for resetting and releasing said second digital counter at the beginning of each measuring period; and wherein said means for comparing the display location values DK and the identifiying values Mi comprises at least one translator operating as a digital number comparator.
 37. The apparatus as defined in claim 36 wherein said translator is a binary-decimally operating digital number comparator circuit.
 38. The apparatus as defined in claim 36 including means for varying the predetermined association between said values Mi and DK at which said means for comparing emits an output signal, whereby the scale and/or range of the display may be controlled.
 39. The apparatus defined in claim 36, including an adjustable pulse frequency divider connected between the output of said freely running clock pulse generator and the input of said second digital counter, whereby the scale of the display may be varied by changing the frequency of the pulses counted by said second digital counter and without any change in the mode of operation of said translator.
 40. The apparatus defined in claim 36 including pulse frequency reducing means connected between the output of said freely running clock pulse generator and the input of said second digital counter for cutting out individual pulses of said series of central control clock pulses at a logarithmically increasing rate, whereby a logarithmic display can be presented without any change in the mode of operation of said translator.
 41. The apparatus as defined in claim 36 including preprogrammed circuitry means for varying the scale of the display by varying the relationship between the digital values DK and Mi.
 42. The apparatus defined in claim 41 including circuit means responsive to the measured value information for stopping the counting of said second digital counter during a measuring period.
 43. The apparatus defined in claim 42 wherein said apparatus is utilized in an echo sounding system and wherein said circuit means for stopping the counting of said digital counter is connected to the receiver amplifier of said system and is responsive to a received bottom echo signal (Be) to stop said counter, whereby the value Mi in said counter also serves as the measured value mi.
 44. The apparatus defined in claim 43 wherein said circuit means for stopping the counting of said second digital counter includes: a gate connected between the output of said freely running clock pulse generator and the input of said second digital counter; and switch means for controlling said gate to selectively cause the stopping of the counting of said second digital counter either upon the receipt of said bottom echo signal or upon the output of said second digital counter reaching a predetermined count.
 45. The apparatus of claim 44 wherein said switch means automatically causes the resetting and the releasing of said second digital counter to begin a new measuring period after transfer of the value Mi into said memory circuit.
 46. The apparatus of claim 43 further comprising means including an integrating and threshold value circuit for controlling the amplification factor of said receiving amplifier in accordance with the momentary occupation density of the memory location of said memory circuit.
 47. The apparatus defined in claim 31 including auxiliary data input means for supplying digitally coded auxiliary data (Zi) associated with the measured values (mi) to the input of said memory circuit for storage therein together with the associated measured values.
 48. The apparatus as defined in claim 32 wherein said recorder is an echograph with a rotating stylus band on which said writing stylus is connected, and wherein said stylus band includes said means for emitting said series of display location pulses (Id).
 49. Apparatus as defined in claim 30 wherein said means for quantizing a given display period comprises means coupled to the said writing means and responsive to the relative position thereto for directly emitting coded position-dependent display location parameters (DK).
 50. The apparatus defined in claim 31 wherein each measured value stored in the memory location is provided with an additional indication representative of the quality of the stored data; and wherein said apparatus further includes: means for comparing each new measured value (mi), before it is written into the memory circuit, with the comparable measured value (mi) stored therein, and (1) in the event of coincidence within a given tolerance range (tol) between the compared values, changing the value of the indications representative of the quality of the measured value information (hereinafter referred to as the comparison value signal Il) stored in the memory to an upgraded value, and (2) in the event of no coincidence within a given tolerance range (tol) between the compared values, causing the new measured value to be stored in an available free location in said memory circuit with a minimum comparison value (Ilmin).
 51. The apparatus defined in claim 50 wherein said means for comparing each new measured value before it is written into the memory circuit includes: a digital comparator means having one input connected to the read-out access of said memory circuit, wherein the data is being continuously shifted in a rapid sequence, and a second input connected in the input path for the input data to the memory circuit; an adjustable tolerance signal generating means connected to a further input of said digital comparator means for setting the coincidence tolerance range, said comparator means having a first output connected to the write-in access of said memory circuit and a second output, said comparator means providing an output signal at said second output whenever information is to be written into the particular memory location then present at read-out access of said memory means; and an evaluator circuit, having one input connected to said second output of said comparator means, and a second input connected to said memory means so as to read the stored comparison value signals (Il), said evaluator circuit being responsive to a signal at said one input thereof to upgrade the value of the comparison value signal being read and change the value thereof in the memory circuit location.
 52. The apparatus of claim 51 wherein upon coincidence between two compared values, said comparator means causes the new measured value to be written into the memory circuit in place of the previously stored value.
 53. The apparatus of claim 51 wherein said evaluator means is a forward and backward counting circuit and wherein said evaluator means causes a marker (n) to be stored in each memory location in which information for the measuring period (Lm) being processed is written and said marker to be erased during a subsequent cycle of the data in said memory circuit before the measured information from the next measuring period (Lm+1) is processed; and wherein said apparatus further includes a cleaning circuit means which is responsive to said stored markers during said subsequent cycle for causing said evaluator means to downgrade the comparison value signal (Il) associated with each memory location not provided with a marker (n).
 54. The apparatus defined in claim 53 wherein said evaluator means is a forward and backward counting counter circuit according to the Gray code for numerical values between 0 and 3 for the comparison values (Il).
 55. The apparatus defined in claim 53 including a transfer circuit and at least one intermediate memory connected in series between said second input of said comparator means and the data inputs for the information to be stored, each intermediate memory having a number Of flipflop stages corresponding to the maximum number of bits for the total input data (mi, Mi, Zi) to be stored in a memory location once per measuring period (Lm).
 56. The apparatus defined in claim 50 including means for passing only stored values of Mi which are associated in the memory with an optimum comparison value (Ilopt) to said means for comparing each consecutive digital location value DK with the identifying values Mi during a display period.
 57. The apparatus defined in claim 31 wherein said drive means for said display means has its sequence of movement selected so that said marking means is disposed within one display section (ld) at least during one cycle of the information (mi, Zi) through said memory circuit.
 58. The apparatus defined in claim 36 wherein said drive means for said display means has its sequence of movement selected so that said marking means is disposed within one display section (ld) at least during one cycle of the information (mi, Zi) through said memory circuit; and wherein the said read-out means includes a gate responsive to an output signal from said translator, and a digital/analog converter for converting the digital signals read out of said memory circuit to analog signals for display.
 59. The apparatus defined in claim 58 wherein said digital/analog converter comprises a writing voltage source, the output value of which controls the intensity of the display mark representing the measured value.
 60. The apparatus defined in claim 59 wherein the information being measured is the time for the return of the echo of a transmitted pulse; wherein said display means is a recording echograph and wherein the output signal of said writing voltage source is connected via said gate to the contact rail for the writing stylus of said echograph to provide a mark at the appropriate display location.
 61. The apparatus defined in claim 39 wherein said second digital counter is a combination of a primary counter and a carry counter connected thereto which has a lesser number of bit locations than said primary counter, said primary and carry counters having parallel outputs.
 62. The apparatus defined in claim 61 wherein said primary counter has a number of stages sufficient to count a fraction of the values Mi of a measuring period Lm, measured by the quantization into measuring intervals corresponding to the desired resolution, and said primary counter starting its count over again during a measuring period (Lm) each time a carry pulse (Ic) has been transmitted to the carry counter.
 63. The apparatus defined in claim 62 further including a digital comparator means having one input connected to the parallel outputs of said primary counter and a second input connected to said memory for comparing each new measured value obtained during a measuring period (Lm) with a corresponding value previously stored in said memory circuit, and for causing values for which no coincidence occurs to be written in a new location of said memory circuit; a partial section signal generating means for selectively providing a digital signal, which is coded in the same code as the digital code utilized in said primary and carry counters, having a value representative of a selected partial section of the measuring period (Lm); signal inverting means having parallel outputs and its input connected to the output of said partial section signal generating means; a digital adder for adding each of the outputs of said inverting means, with the exception of the output representing the lowest order bit, with the corresponding output of said carry counter; and an AND gate having its inputs connected to the outputs of said adder and its output connected to an enabling input of said comparator, whereby only measured values occurring within the selected partial section of the measuring period will be compared and stOred.
 64. The apparatus defined in claim 63 wherein said adder is provided with an additional adder stage the output of which is connected to said comparator and represents the highest order bit of said primary counter, the inputs of said additional adder stage being connected to the output of said inverting means representing the lowest order bit and the output of said primary counter representing the highest order digit, whereby the output of said primary counter representing the highest order digit is not directly coupled to said comparator means bit only via said additional adder stage.
 65. Apparatus as defined in claim 63 wherein said carry counter is provided, in addition to the number of bit locations required to count out the partial sections of the entire measuring period, with a further, highest-value bit location for producing a final carry pulse (Icc1) at the output thereof after passage of the last partial section of the measuring period (Lm); and further including switching circuit means responsive to an input signal thereto for stopping and resetting said primary and carry counters, said output of said highest-value bit location of said carry counter being coupled to the input of said switching circuit means.
 66. The apparatus defined in claim 65 wherein said output of said highest-value bit location of said carry counter is connected with the input of said switching circuit means via an OR gate; wherein said adder provides a carry pulse (Icc2) at a carry output at the end of a partial section selected by means of the signal from said partial section signal generator; and wherein said carry output of said adder is connected to the other input of said OR gate.
 67. The apparatus defined in claim 58 including a range marker signal generating means, the output of said range marker signal generating means being coupled to said marking means via said gate to cause an indication representative of the particular display range being utilized to appear in the display.
 68. The apparatus defined in claim 63 including a range marker signal generating means, the output of said range marker signal generating means being coupled to said marking means via said gate to cause an indication representative of the particular display range being utilized to appear in the display; and wherein said range marker signal generating means has its input coupled to the output of said partial section signal generating means, whereby said range marker signal generating means automatically causes an indication of the selected partial section of the measuring period.
 69. The apparatus defined in claim 68 including a blocking key for temporarily blocking the function of said range marker signal generating means during a display period.
 70. The apparatus defined in claim 47 wherein said apparatus is utilized for measuring the returned echoes of transmitted signals; wherein said auxiliary data input means includes a fundamental frequency discriminator which is connected between the output of an echo signal receiver and the input of an auxiliary data signal generating means for providing auxiliary data signals to identify different frequency based measured values (mi) and to identify measured values (mi) which have different fundamental frequencies in their bottom echo signals (Be, Be1, ...).
 71. The apparatus defined in claim 59 wherein said apparatus is utilized in an echo sounding system; wherein said gate has a bistable characteristic; and further including a backward counting digital counter means for storing a value representative of the return echo time; means for supplying said backward counting digital counter means with said value representative of the return echo time at the beginning of a display period; said backward counting digital counter means being responsive to the output signal from said translator to close said gate and to begin its backward count, and to open said gate when it has counted out the value momentarily stored therein.
 72. The apparatus defined in claim 71 wherein said means for supplying said backward counting digital counter means includes a further digital counter means for counting the pulses from said free running control clock pulse generator, and means for stopping the count of said further digital counter upon receipt of a returned echo pulse whereby the value stored in said further digital counter is the measured value (mi).
 73. The apparatus defined in claim 59, including an amplitude coder means for providing a coded output signal proportional to the amplitude of a measured value input signal to said apparatus; and wherein said writing voltage source is responsive to the output signal from said amplitude coder means to vary the intensity of the output thereof.
 74. The apparatus defined in claim 39 wherein said apparatus is utilized in an echo sounding system; wherein the value Mi present in said second digital counter at the time of receipt of an echo from a transmitted signal is the measured value (mi); and wherein an adjustable range preselector means is provided for furnishing a digital value equal to a preselected starting identifying value (Ma) at the beginning of each measuring period (Lm); and means for transferring said value Ma to said second digital counter at the beginning of each measuring period.
 75. The apparatus defined in claim 39 wherein said apparatus is utilized in an echo sounding system; wherein the transmission of a signal by means of a signal transmitter initiates the measuring period (Lm) and the starting of the counting by said second digital counter; wherein the value in said second digital counter upon receipt of an echo of a transmitted signal is proportional to the travel time of said transmitted signal; and wherein said apparatus further includes means for triggering said signal transmitter whenever said second counter reaches a predetermined count following the beginning of a measuring period (Lm).
 76. The apparatus defined in claim 31 wherein said apparatus is utilized in an echo sounding system on a surveying vessel; wherein the transmission of a signal by means of a signal transmitter initiates the measuring period (Lm) and the starting of the counting by said second digital counter; wherein the value in said second digital counter upon receipt of an echo of a transmitted signal is proportional to the travel time of said transmitted signal; and wherein said apparatus further includes means for triggering said signal transmitter in accordance with the environmental conditions on said surveying vessel to provide optimum conditions for the transmission.
 77. The apparatus defined in claim 76 wherein said means for triggering said signal transmitter comprises an inclinometer.
 78. The apparatus defined in claim 76 wherein said means for triggering said signal transmitter comprises a lift accelerometer for said surveying vessel.
 79. The apparatus defined in claim 31 wherein said apparatus is utilized in an echo sounding system on board a surveying vessel; wherein said display means is an echograph having a marking means in the form of a writing stylus which traverses the record on said echograph in a uniform manner and transverse to the longitudinal direction of said record; and wherein said apparatus further includes a first transmitting means for echo soundings in shallow water; a stylus end of travel contact means on said echograph for producing a signal when said writing stylus has reached the end of a display range during each display period, said first transmitting means being responsive to the signal produced by said end of travel contact means to transmit a signal; a first receiver for the echoes of signals transmitted by said first transmitting means, the output of said first receiver being coupled to the input of said memory circuit for storing the received bottom echo signals in timed sequence in adjacent memoRy locations; and a start of travel contact means on said echograph for producing a signal when said writing stylus begins its travel over the display range at the beginning of each display period, said read-out means being responsive to the signal from said start of travel contact means to read out the information stored in said memory circuit and feed the same to said writing stylus, whereby the speed of the drive means for said writing stylus may be set at an optimum fast speed for displaying information from shallow water echo soundings.
 80. The apparatus defined in claim 79 including: a second transmitter means and a second receiver means for deep water echo soundings; and an operational mode switch for selectively disconnecting said end of travel contact means and said start of travel contact means from said first transmitter means and the output of said memory circuit, respectively, and for connecting said start of travel contact means to said second transmitter means and the output of said second receiving means to said writing stylus.
 81. The apparatus defined in claim 80 including an analog/digital converter connected between the input of said memory and the output of said first transmitter means and a digital/analog converter connected between the output of said memory circuit and said operational mode switch. 